The Geitvann lead-copper mineralisation of Porsangerhalvøya in northern Norway occurs in shallowmarine
sediments in the Kolvik Nappe, which is part of the Caledonian Kalak Nappe Complex.
Lithologically, the rocks of the Kolvik Nappe consist of arkosic psammites and pelitic to semi-pelitic
schists. A swarm of metadolerite dykes and sills occurs in the mineralised area. The stratabound
mineralisation occurring in calcareous metasandstone beds comprises galena, chalcopyrite, pyrrhotite
and sphalerite. Lead isotope data give a model age of about 940 Ma with low µ-value. The Geitvann deposit has a similar isotopic composition to that of sulphide deposits in volcanic rocks in the Grenvillian Central Metasedimentary Belt in Canada.